Method of treating atherosclerosis and hypercholesterolemia

ABSTRACT

A method of treatment of cardiovascular diseases comprising the use of an LXR agonist impregnated on a stent is disclosed.

FIELD OF THE INVENTION

This invention relates to a novel method for the treatment ofatherosclerosis and/or hypercholesterolemia.

BACKGROUND OF THE INVENTION

Cardiovascular Disease is a leading cause of death and disability amongmost of the world's population but particularly in developed anddeveloping countries. Atherosclerosis is one of the more common forms ofcardiovascular disease and it leads to insufficient blood supply tocritical body organs resulting in for example, heart attack, stroke andkidney failure. Atherosclerosis also causes complications in peoplesuffering from hypertension and diabetes.

While the processes causing atherosclerosis are complex and notcompletely understood, an underlying pathology to the numerous theoriesfor the cause of atherosclerosis and atherosclerotic lesion formationare for example, an increase in serum cholesterol, and the accumulationof cholesterol esters in the arterial wall. A similar pathology is alsoimplicated in restenosis, the so-called recurrence of stenosis orarterial stricture after corrective surgery. Restenosis has beendescribed as an accelerated atherosclerosis induced by injury(Forrester, J. S., et al., JACC, 17(3):758-769 (1991)).

Restenosis has been observed to occur after coronary artery bypasssurgery, heart transplantation, atherectomy, laser ablation, and balloonangioplasty. Restenosis is most common after balloon angioplasty; alsoreferred to as percutaneous transluminal coronary angioplasty, which iswidely used as a treatment modality in patients with coronary arterydisease to reduce lumen obstruction and improve coronary blood, flow. Itis estimated that between 25-35% of patients develop restenosis within1-3 months after balloon coronary angioplasty, necessitating furtherinterventions such as repeat angioplasty or coronary bypass surgery.

Oxysterol (LXR) receptors have been found to mediate inhibition ofcholesterol absorption (uptake) and promote cholesterol efflux in theartery indicating that compounds activating LXR may be used as therapiesto treat restenosis. LXR receptors in combination with retinoid (X)receptors (RXR) serve as regulators of cholesterol balance bycontrolling reverse cholesterol transport from peripheral tissues, bileacid synthesis in the liver, and cholesterol absorption in the intestine(see Mangelsdorf et al., Regulation of Absorption and ABC-1 MediatedEfflux of Cholesterol by RXR Heterodimers, Research Articles:publishedMay 31, 2000.

LXR and RXR agonists have also been shown to have a detrimental effecton plasma triglyceride levels via direct action at the liver (Schultz etal., Role of LXRs in Control of Lypogenesis, Genes and Development,14:2831-7400). A method is therefore needed that advantageously utilizesthe beneficial effects of LXR agonists while avoiding or minimizing thedetrimental effects on plasma triglycerides. However, none of theavailable methods has been found to be sufficiently effective inlowering cholesterol absorption in a sustained manner to theatherosclerotic lesion and also limit, minimize, or ameliorate thedetrimental effect on triglyceride levels via direct action in theliver.

SUMMARY OF THE INVENTION

The present invention provides a method for lowering cholesterolabsorption in a sustained manner by the use of a localized delivery ofLXR and/or RXR agonists while also limiting, minimizing, or amelioratingthe detrimental effect of LXR agonists on triglyceride levels via directaction in the liver.

The present invention relates to a method for localized delivery of LXR,and/or RXR ligands to atherosclerotic lesions to reduce the incidence ofrestinosis.

The present invention provides methods for the localized delivery of LXRand/or RXR agents to atherosclerotic lesions via catherizationtechniques.

The present invention provides a method for treating stroke and/orpreventing restenosis by using an LXR agonist impregnated on a stent tokeep the arteries open and simultaneously elevate HDL levels.

The present invention also relates to the use of a combination therapyof LXR agonist, RXR agonist and stent for the treatment and/orprevention of Cardiovascular Diseases.

The present invention relates to the use of a pharmaceutical compositioncomprising a therapeutically effective amount of an LXR agonistimpregnated on a stent for the manufacture of a medicament for thetreatment and/or prevention of Cardiovascular Diseases.

The present invention relates to the use of a pharmaceutical compositioncomprising a therapeutically effective amount of a combination of LXRagonist and RXR agonist impregnated on a stent for the manufacture of amedicament for the treatment and/or prevention of CardiovascularDiseases.

II. DEFINITIONS

The terms, “mammal” and “mammalian” include human and domesticatedquadrupeds.

The term, “Cardiovascular Diseases” refers to diseases such as coronaryocclusion, congestive heart failure, cardiac alternation, ventricularaneurysm, mural aneurysm, myocardial infarction, cardiac arrest, cardiacdysrhythmia, cardiac edema, cardiac dyspnea, cardiac failure,tachycardia, cardiac hemoptysis, cardiac incompetence, cardiac murmur,cardiac syncope, cardiac tamponade.

The term “hypercholesterolemia” refers to an abnormally large amount ofcholesterol present in the cells and/or plasma of circulating blood.

The term “antihypercholesterolemic agent” refers to agents that inhibitcholesterol absorption i.e. liver X receptor (LXR) ligands for thepotential treatment of hypercholesterolemia. Such inhibitors include forexample, LXR agonists, derivatives and analogs of LXR ligands such asT-0901317 and TU-314407, as well as derivatives and analogs ofhydroxy-substituted azetidone compounds such as ezemtimibe (Sch-58235)and Sch-60663.

“Administering” as used herein is intended to include routes ofadministration, which allow the antihypercholesterolemic agent toperform its intended function of lowering cholesterol absorption. Suchadministration includes systemic and local or site specificadministration by means of a drug delivery catheter, or implantation ofa drug-carrying device.

The term “treatment” as used herein refers to the amelioration,inhibition, prevention of recurrence, reduction in severity or effect,of cardiovascular diseases including but not limited tohypercholesterolemia, and artheroscierosis by the use of a stentimpregnated with LXR ligand(s) and/or RXR ligands.

The term “effective amount” as used herein refers to the amount of LXRligand(s) and/or RXR ligands necessary or sufficient to lower theabsorption of cholesterol in the atherosclerotic lesion and/or elevatethe level of HDL. The effective amount can vary depending on factorsknown to those of skill in the art, such as mode and regimen ofadministration, the size of the subject, severity ofhypercholesterolemia, etc. One of skill in the art would be able toconsider such factors and make the determination regarding effectiveamount.

“Pharmaceutically acceptable carrier” refers to any substanceco-administered with the antihypercholesterolemic agent and which allowsthe compound to perform its intended function. Examples of such carriersinclude solutions, solvents, dispersion media, delay agents, emulsions,microparticles and the like for combination therapies.

The term, “alkyl” by itself or as part of another substituent means,unless otherwise defined, a straight or branched chain monovalenthydrocarbon radical such as methyl, ethyl, n-propyl, isopropyl, n-butyl,tertiary butyl, sec-butyl, n-pentyl, and n-hexyl.

The term, “alkenyl” employed alone or in combination with other termsmeans a straight chain or branched monovalent hydrocarbon group havingthe stated number ranges of carbon atoms, and typified by groups such asvinyl, propenyl, crotonyl, isopentenyl, and various butenyl isomers.

The term, “hydrocarbyl” means an organic group containing only carbonand hydrogen.

The term, “halo” means fluoro, chloro, bromo, or iodo.

The term “heterocyclic radical” refers to radicals derived frommonocyclic or polycyclic, saturated or unsaturated, substituted orunsubstituted heterocyclic nuclei having 5 to 14 ring atoms andcontaining from 1 to 3 hetero atoms selected from the group consistingof nitrogen, oxygen or sulfur. Typical heterocyclic radicals arepyrrolyl, pyrrolodinyl, piperidinyl, furanyl, thiophenyl, pyrazolyl,imidazolyl, phenylimidazolyl, triazolyl, isoxazolyl, oxazolyl,thiazolyl, thiadiazolyl, benzo(b)thiophenyl, carbazolyl, norharmanyl,azabenzo(b)thiophenyl, benzofuranyl, dibenzofuranyl, dibenzothiophenyl,indazolyl, imidazo(1.2-A)pyridinyl, benzotriazolyl, anthranilyl,1,2-benzisoxazolyl, benzoxazolyl, benzothiazolyl, purinyl, pyridinyl,dipyridylyl. phenylpyridinyl, benzylpyridinyl, pyrimidinyl,phenylpyrimidinyl, pyrazinyl, 1,3,5-triazinyl, quinolinyl, phihalazinyl,quinazolinyl,morpholino, thiomorpholino, homopiperazinyl,tetrahydrofuranyl, tetrahydropyranyl, oxacanyl, 1,3-dioxolanyl,1,3-dioxanyl, 1,4-dioxanyl, tetrahydrothiophenyl,pentamethylenesulfadyl, 1,3-dithianyl, 1,4-dithianyl, 1,4-thioxanyl,azetidinyl, hexamethyleneiminium, heptamethyleneiminium, piperazinyl andquinoxalinyl.

III. THE LXR AGONISTS OF THE INVENTION

One embodiment of the practice of the present invention is the use of apharmaceutical composition comprising a therapeutically effective amountof an LXR agonist of formula I impregnated on a stent for the treatmentand/or prevention of Cardiovascular Diseases

or a pharmaceutically acceptable salt thereof, wherein:

-   -   Ar¹ and Ar² are independently selected from the group consisting        of aryl and R⁴-substituted aryl;    -   Ar³ is aryl or R⁵-substituted aryl;    -   X, Y and Z are independently selected from the group consisting        of —CH₂—, —CH(lower alkyl)- and    -   —C(dilower alkyl)-;    -   R and R² are independently selected from the group consisting of        —OR⁶, —O(CO)R⁶, —O(CO)OR⁹ and —O(CO)NR⁶R⁷;    -   R¹ and R³ are independently selected from the group consisting        of hydrogen, lower alkyl and aryl;    -   q is 0 or 1; r is 0 or 1; m, n and p are independently 0, 1, 2,        3 or 4; provided that at least one of q and r is 1, and the sum        of m, n, p, q and r is 1, 2, 3, 4, 5 or 6; and provided that        when p is 0 and r is 1, the sum of m, q and n is 1, 2, 3, 4 or        5;    -   R⁴ is 1-5 substituents independently selected from the group        consisting of lower alkyl, —OR⁶, —O(CO)R⁶, —O(CO)OR⁹,        —O(CH₂)₁₋₅OR⁶, —O(CO)NR⁶R⁷, —NR⁶R⁷. —NR⁶(CO)R⁷, —NR⁶(CO)OR⁹,        —NR⁶(CO)NR⁷R⁸, —NR⁶SO₂R⁹, —COOR⁶, —CONR⁶R⁷, —COR⁶, —SO₂NR⁶R⁷,        S(O)₀₋₂R⁹, —O(CH₂)₁₋₁₀—COOR⁶, —O(CH₂)₁₋₁₀CONR⁶R⁷, -(lower        alkylene)COOR⁶, —CH═CH—COOR⁶, —CF₃, —CN, —NO₂ and halogen;    -   R⁵ is 1-5 substituents independently selected from the group        consisting of —OR⁶, —O(CO)R⁶, —O(CO)OR⁹, —O(CH₂)₁₋₅OR⁶,        —O(CO)NR⁶R⁷, —NR⁶R⁷, —NR⁶(CO)R⁷, —NR⁶(CO)OR⁹, —NR⁶(CO)NR⁷R⁸,        —NR⁶SO₂R⁹, —COOR⁶, —CONR⁶R⁷, —COR⁶, —SO₂NR⁶R⁷, —S(O)₀₋₂R⁹,        —O(CH₂)₁₋₁₀—COOR⁶, —O(CH₂)₁₋₁₀CONR⁶R⁷, -(lower alkylene)COOR⁶,        —CH=CH—COOR⁶;    -   R⁶ R⁷ AND R⁸ are independently selected from the group        consisting of hydrogen, lower alkyl, aryl and aryl-substituted        lower alkyl; and    -   R⁹ is lower alkyl, aryl or aryl-substituted lower alkyl.

Another embodiment of the practice of the present invention is the useof a pharmaceutical composition comprising a therapeutically effectiveamount of an LXR agonist of formula II impregnated on a stent for thetreatment and/or prevention of Cardiovascular Diseases wherein formulaII is represented by the:

a pharmaceutically acceptable salt thereof, wherein

-   -   Ar is an aryl group;    -   R¹ is a member selected from the group consisting of —OH,—CO₂H,        —O—(C₁-C₇)alkyl, —OC(O)—(C₁-C₇)alkyl, —O—(C₁-C₇)heteroalkyl,        —OC(O)—(C₁-C₇)heteroalkyl, —NH₂,—NH(C₁-C₇)alkyl,        —N((C₁-C₇)alkyl)₂ and —NH—S(O)₂—(C₁-C₅)alkyl;    -   R² is a member selected from the group consisting of        (C₁-C₇)alkyl or (C₁-C₇)heteroalkyl, aryl and aryl(C₁-C₇)alkyl;    -   X¹, X², X³, X⁴, X⁵ and X⁶ are each independently a member        selected from the group consisting of H,(C₁-C₅)heteroalkyl, F        and Cl, with the proviso that no more than three of X¹ through        X⁶ are H, (C₁-C₅)alkyl or (C₁-C₇)heteroalkyl; and    -   Y is a divalent linking group selected from the group consisting        of —N(R¹²)S(O)_(m)—, —N(R¹²)S(O)_(m)N(R¹³)—, —N(R¹²)C(O)—,        —N(R¹²)C(O)N(R¹³)—, —N(R¹²)C(S)— and —N(R¹²)C(O)O—;    -   Wherein R¹² and R¹³ are each independently selected from the        group consisting of H, (C₁-C₇)alkyl, (C₁-C₇)heteroalkyl, aryl        and aryl(C₁-C₇)alkyl, and optionally when Y is —N(R¹²)S(O)_(m)—        or —N(R²)S(O)_(m)N(R¹³)—, R¹² forms a five- or six-member ring        fused to Ar or to R² through covalent attachment to Ar or to R²        through covalent attachment to Ar or to R², respectively; and        the subscript m is an integer of from 1 to 2;    -   With the proviso that when R¹ is OH, and —Y—R is        —N(R¹²)S(O)_(m)—R² or —N(R¹²)C(O)N(R¹³)—R² and is attached to a        position para to the quaternary carbon attached to Ar, and when        R² is phenyl, benzyl or benzoyl, then i) at least one of R¹² or        R¹³ is other than hydrogen and contains an electron-withdrawing        substitutent, or ii) R² is substituted with a moiety other than        amino, acetamido, di(C₁-C₇)alkylamino, 1(C₁-C₇)alkylamino,        halogen, hydroxy, nitro, or (C₁-C₇)alkyl, or iii) the benzene        ring portion of R² is substituted with at least three        independently selected groups in addition to the Y group or        point of attachment to Y. Compounds of formula H are disclosed        in PCT application number PCT/US00/06611, filed Mar. 15, 2000,        of which the method of preparation and examples are incorporated        herein.

Methods and procedures for preparing compounds of formula I aredisclosed in PCT application Number PCT/US94/10099, filed Sep. 14,1994,and are incorporated herein by reference.

Methods and procedures for preparing compounds of formula II aredisclosed in PCT application number PCT/US00/06611, filed Mar. 15, 2000,and are incorporated herein by reference.

A compound of formula I and/or formula II along with a carrier and orexcipients is impregnated on a stent by impregnation methods known toone of skill in the art, including for example, spray-on techniques withor without pharmaceutically acceptable adhesion agents. The stent mayalso be immersed in a slurry or solution of the Active ingredient in asuitable solvent, i.e. methylene chloride or acetone followed byevaporation or concentration of the solution or solvent to effectimpregnation of the Active ingredient on the stent. The impregnatedstent may be further dried, annealed or sealed with a sealing agent toprevent flaking off or break-offs. Annealing and/or sealing agents forthe purpose are known to one of skill in the art.

IV. METHODS OF USING THE INVENTION

The LXR agonist/stent or LXR/RXR agonist/stent combinations describedherein are believed to achieve their beneficial therapeutic action bysimultaneously providing stenting action and cholesterol efflux, andthereby treating and/or preventing artherosclerosis and restenosis.

The method of the invention for inhibiting restenosis and effectingcholesterol efflux comprises contacting arterial cavity with atherapeutically effective amount of an LXR agonist or a combination ofan LXR agonist and an RXR agonist adsorbed on, or impregnated on a stentas described herein including a salt or a prodrug derivative of LXRand/or RXR agonist thereof.

Another aspect of this invention relates to a method for treatingCardiovascular Diseases such as coronary occlusion, congestive heartfailure, cardiac alternation, ventricular aneurysm, mural aneurysm,myocardial infarction, cardiac arrest, cardiac dysrhythmia, cardiacedema, cardiac dyspnea, cardiac failure, tachycardia, cardiachemoptysis, cardiac incompetence, cardiac murmur, cardiac syncope,cardiac tamponade.

As noted previously, the compounds useful in this invention inhibitcholesterol absorption or resorption. By the term, “inhibiting” is meantthe prevention or therapeutically significant reduction in the level ofcholesterol and/or prevention or therapeutically significant reductionin the risk of restenosis.

The specific dose of a compound administered according to this inventionto obtain therapeutic or prophylactic effect will, of course, bedetermined by the particular circumstances surrounding the case,including, for example, the compound administered, the route ofadministration and the condition being treated. Typical daily doses willcontain a non-toxic dosage level of from about 0.01 mg/kg to about 50mg/kg of body weight of an active compound of this invention.

The LXR agonist, RXR agonist, or LXR/R combination agonist compound(s)impregnated on a stent may be administered directly at theartherosclerotic lesion via a catetherization technique. When the LXRagonist is impregnated on a stent, the dose is a factor of 2 to 20 timeshigher than a single therapy, single dose formulation. In the caseswhere the LXR agonist compound is impregnated on a stent, a slow releaseformulation of LXR agonist compound is applied to effect slow and timedrelease of formulation comprising the compound.

Pharmaceutical formulations of the invention are prepared byimpregnating e.g., by spray-on, a therapeutically effective amount ofthe LXR agonist, RXR agonist, or LXR/RXR combination agonist compound(s)on a stent device. The spray-on pharmaceutical formulations are preparedby known procedures using known and readily available ingredients.

For the pharmaceutical formulations any suitable carrier known in theart can be used. In such a formulation, the carrier may be a solid,liquid, or mixture of a solid and a liquid. For example, the Activeingredient may be dissolved in a suitable solvent at a concentration ofabout 2 to 200 mg/ml in a 4% dextrose/0.5% Na citrate aqueous solution.Solid form formulations for impregnation on the stent include powdersand pastes. A solid carrier can be one or more substance, which may alsoact as lubricants, solubilizers, suspending agents, and pharmaceuticallyacceptable adhesive agents.

In powders, the carrier is a finely divided solid having the necessarybinding properties in suitable proportions, which is in an admixturewith the finely divided Active ingredient. The powders will typically besprayed on optionally followed by spray-on of annealing or sealingagents. The powders preferably contain from about 1 to about 99 weightpercent of the Active ingredient. Suitable solid carriers are magnesiumcarbonate, magnesium stearate, talc, sugar lactose, pectin, dextrin,starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, pharmaceutically acceptable low melting waxes, andpharmaceutically acceptable adhesives.

The Active ingredient can be dissolved or suspended in apharmaceutically acceptable carrier, such as sterile water, sterileorganic solvent or a mixture of both. The Active ingredient can often bedissolved in a suitable organic solvent, for instance aqueous propyleneglycol. Dispersing the finely divided Active ingredient in aqueousstarch or sodium carboxymethyl cellulose solution, or binder orpharmaceutically acceptable adhesive may result in other compositions.The solution or suspension is then impregnated on a stent by coating theadmixture of active ingredient on the stent and allowing the solvent toevaporate slowly under vacuum until nearly all solvent or liquid isevaporated.

The following pharmaceutical formulations are illustrative only and arenot intended to limit the scope of the invention in any way. “Activeingredient”, refers to a compound according to Formula (I) or (II) or apharmaceutically acceptable salt, solvate, or prodrug thereof which isto be impregnated on a stent. Slow Release Formulation 1 Hard gelatinpowder to be sprayed on a stent is prepared using the followingingredients: Quantity (mg/capsule) Active ingredient 250 Starch, dried200 Magnesium stearate  10 Total 460 mg

Formulation 2 A solid composition of formula I or II to be sprayed on astent is prepared using the ingredients below: Quantity (mg/tablet)Active ingredient 250 Cellulose, microcrystalline 400 Silicon dioxide,fumed  10 Stearic acid  5 Total 665 mg

The components are blended and compressed to form a solid each weighing665 mg which is then sprayed on the stent either as a slurry or admixedwith a pharmaceutically acceptable adhesion agent.

1. A method for lowering cholesterol absorption in a sustained manner bythe use of a localized delivery of LXR and/or RXR agonists while alsolimiting, minimizing, or ameliorating the detrimental effect of LXRagonists on triglyceride levels via direct action in the liver.
 2. Amethod for treating and/or preventing Cardiovascular Disease comprisingimpregnation of LXR agonists on a stent device.
 3. A method for treatingand/or preventing Cardiovascular Diseases comprising impregnation of RXRagonists on a stent device.
 4. A method for treating and/or preventingCardiovascular Diseases comprising impregnation of LXR and/or RXRagonists on a stent device.
 5. A method according to claim 1 or 3wherein the LXR agonist is selected from a group consisting of: acompound of formula I, and a compound of formula II.
 6. A compositioncomprising a therapeutically effective amount of a LXR agonistimpregnated on a stent.
 7. A composition comprising a therapeuticallyeffective amount of a RXR agonist impregnated on a stent.
 8. Acomposition according to claim 6 or 7 wherein the LXR or RXR agonist isimpregnated to effect a time-release (slow-release) formulation. 9.(canceled)
 10. (canceled)